Design Patterns help us to reuse the experience of object-oriented software design experts by understanding the recurring design as object, class and their interaction and documenting the design systematically, when we design object-oriented software. Design patterns should be not only specific to the problem at hand but also general enough to address future problems and requirements.
In this thesis, we propose a new design pattern called 'Folder' that can be used in development of security service in application. Folder design pattern is extracted from the security service of X.400 application which is also known as Message Handling System. Folder maintains objects each of which has an operation and its counter operation as methods in order to ease interactions between peer entities. Folder also has a register method for the operation and its counter operation, and provide a test method for checking the functionality of the operation and its counter operation. The benefit of using Folder design pattern in security service is flexiblity which enables us to use any encryption algorithm. In addition, Folder design pattern makes it easy to understand the characteristic of the security service. We show that Folder design pattern can be used to develop the security service of Message Handling System efficiently.
